station: fix crash when deauth comes before FT work completes

If the FT-Authenticate frame has been sent then a deauth is received
the work item for sending the FT-Associate frame is never canceled.
When this runs station->connected_network is NULL which causes a
crash:

src/station.c:station_try_next_transition() 7, target xx:xx:xx:xx:xx:xx
src/wiphy.c:wiphy_radio_work_insert() Inserting work item 5843
src/wiphy.c:wiphy_radio_work_insert() Inserting work item 5844
src/wiphy.c:wiphy_radio_work_done() Work item 5842 done
src/wiphy.c:wiphy_radio_work_next() Starting work item 5843
src/netdev.c:netdev_mlme_notify() MLME notification Remain on Channel(55)
src/ft.c:ft_send_authenticate()
src/netdev.c:netdev_mlme_notify() MLME notification Frame TX Status(60)
src/netdev.c:netdev_link_notify() event 16 on ifindex 7
src/netdev.c:netdev_mlme_notify() MLME notification Del Station(20)
src/netdev.c:netdev_mlme_notify() MLME notification Deauthenticate(39)
src/netdev.c:netdev_deauthenticate_event()
src/netdev.c:netdev_mlme_notify() MLME notification Disconnect(48)
src/netdev.c:netdev_disconnect_event()
Received Deauthentication event, reason: 7, from_ap: true
src/station.c:station_disconnect_event() 7
src/station.c:station_disassociated() 7
src/station.c:station_reset_connection_state() 7
src/station.c:station_roam_state_clear() 7
src/netconfig.c:netconfig_event_handler() l_netconfig event 2
src/netconfig-commit.c:netconfig_commit_print_addrs() removing address: yyy.yyy.yyy.yyy
src/resolve.c:resolve_systemd_revert() ifindex: 7
[DHCPv4] l_dhcp_client_stop:1264 Entering state: DHCP_STATE_INIT
src/station.c:station_enter_state() Old State: connected, new state: disconnected
src/station.c:station_enter_state() Old State: disconnected, new state: autoconnect_quick
src/wiphy.c:wiphy_radio_work_insert() Inserting work item 5845
src/netdev.c:netdev_mlme_notify() MLME notification Cancel Remain on Channel(56)
src/wiphy.c:wiphy_radio_work_done() Work item 5843 done
src/wiphy.c:wiphy_radio_work_next() Starting work item 5844

"Program terminated with signal SIGSEGV, Segmentation fault.",
"#0  0x0000565359ee3f54 in network_bss_find_by_addr ()",
"#0  0x0000565359ee3f54 in network_bss_find_by_addr ()",
"#1  0x0000565359ec9d23 in station_ft_work_ready ()",
"#2  0x0000565359ec0af0 in wiphy_radio_work_next ()",
"#3  0x0000565359f20080 in offchannel_mlme_notify ()",
"#4  0x0000565359f4416b in received_data ()",
"#5  0x0000565359f40d90 in io_callback ()",
"#6  0x0000565359f3ff4d in l_main_iterate ()",
"#7  0x0000565359f4001c in l_main_run ()",
"#8  0x0000565359f40240 in l_main_run_with_signal ()",
"#9  0x0000565359eb3888 in main ()"

src/station.c

@@ -1721,6 +1721,9 @@ static void station_roam_state_clear(struct station *station)
 	l_queue_clear(station->roam_bss_list, l_free);
 
 	ft_clear_authentications(netdev_get_ifindex(station->netdev));
+
+	if (station->ft_work.id)
+		wiphy_radio_work_done(station->wiphy, station->ft_work.id);
 }
 
 static void station_reset_connection_state(struct station *station)